Sarah Nichols

Virtual Reality-Induced Symptoms and Effects (VRISE)

An experimental program of research was carried out to assess the potential health and safety effects of participating in virtual environments (VEs) via head-mounted displays (HMDs). This paper presents the results obtained from nine experiments examining the effects experienced during and after participation in a variety of VR systems, VE designs, and task requirements, for a total participant sample of 148 individuals. A combination of methods including self-report scales, performance measures, physiological indicators, observation, interview, and user attitude/opinion questionnaires were used to measure simulator (VE) sickness, postural instability, psychomotor control, perceptual judgment, concentration, stress, and ergonomics effects. Greatest effects across the different systems, VEs, and exposure times were found for sickness symptoms and physiological measures, with some concern over postural instability and physical ergonomics, also. Although many of the effects were relatively minor and short lived, they were serious for five percent of participants and irritating for a considerable percentage more. The aetiology of the effects is sufficiently different to that for simulators or transport systems to justify us using a new term, virtual reality-induced symptoms and effects (VRISE). Implications are drawn for VR system design, VE specification, and the ways in which industrial use of VR/VE should be planned and supported.

Measurement of presence and its consequences in virtual environments

A sense of presence is one of the critical components required by any effective virtual environment (VE). In contrast, side effects such as sickness may be produced in some virtual environments, detracting from the enjoyment or usefulness of the VE and from subsequent performance of the participant. Both presence and sickness in virtual environments are multifactorial phenomena not easily amenable to understanding or measurement. The first experiment reported here compares use of direct performance measures and rating scales to assess presence, whilst varying the VE display medium (head mounted and desktop displays) and whether or not sound was used in the VE. The second experiment addresses associations between presence, sickness and enjoyment of virtual environment participation. There was enough comparability between a reflex response within the VE and the rating scales to justify future exploration of the former measure of presence. A number of explanations are given for the partial association found between presence and sickness.

Health and safety implications of virtual reality : A review of empirical evidence

For the last 10 years a number of papers have been written that discuss human factors issues associated with virtual reality (VR). The nature of these papers has gradually evolved from speculation and anecdotal report to empirical research. Despite developments in VR technology, some participants still experience health and safety problems associated with VR use-termed VR-induced symptoms and effects (VRISE). The key concern from the literature is VR-induced sickness, experienced by a large proportion of VR participants, but for the majority these effects are mild and subside quickly. This paper makes a number of recommendations regarding the future direction of research into health and safety implications of VR, including the need to take into account the way in which VR is being used when conducting empirical research: first, to ensure that studies consider both effects and their consequences, second, to ensure that empirical trials reflect the actual likely context of VR use; third, to consider interactions between effects: and finally, to consider ways in which effects can be managed.

Static posture tests for the assessment of postural instability after virtual environment use.

The aim of this experiment was to measure the effect of immersion in a virtual environment (VE) on postural stability and examine the relationship between postural stability and self-reported simulator sickness. Forty healthy subjects were exposed to 20 min of immersion in an interactive VE with restricted user movement. The VE was viewed on a head mounted display (HMD) and the subject remained standing throughout the immersion period. Two static postures, normal stance and tandem romberg, were recorded before immersion, immediately after immersion and again at 10 min postimmersion. Performance in each posture was simultaneously measured by recording time that the posture could be maintained and mm path length of body sway over a 30-s period. The results demonstrated differences in the sensitivity of postural stability measurement techniques and variations in inter- and intraindividual responses to measures. Sway magnetometry measured a significant increase in postural instability in normal stance after VE immersion. None of the other measures were sensitive to this change. Postimmersion reports of simulator sickness symptoms indicate that the VE stimulus was provocative and correlation was found between reports of simulator sickness and balance-related symptoms. However, no association between self-reported symptoms and performance measures of postural instability was found.

Theme-based content analysis

Virtual environment and multimedia technology are developing rapidly in many areas. These include visual complexity, the opportunity to provide multi-sensory input and output, affordability and a variety of system designs and applications. Involving the users in the design and development process can result in more appropriate and usable interfaces. In addition, an iterative evaluation throughout the process of technology development can result in a large amount of useful information being gathered from users. However, there can be problems with this?the data collection and analysis process can be time consuming; it can be difficult to report information back to the developers in a meaningful form, and thus the results of the evaluation may not get incorporated into interface design; and some evaluation techniques can be specific to the application (e.g. assessment of learning from an educational virtual environment application) or user group (e.g. people with learning disabilities).This paper presents an evaluation method that has been successfully used in virtual environment and multimedia evaluation at the Virtual Reality Applications Research Team (VIRART), and has overcome some of these problems. Theme-based content analysis (TBCA) is a qualitative method that provides useful, detailed information about user opinions or behaviour, and can also provide general indications of results in the user population by the grouping of data into meaningful categories. A number of different data collection methods can be used (e.g. short interview, open-ended questionnaire questions, observation) allowing the time and expertise of the virtual environment researcher to be most usefully employed, and the needs and abilities of the user population to be met. The analysis process is less time-consuming, and allows both summarization of the results and retention of the raw data. As described in the paper, this flexible method can be applied in a number of different circumstances, with a variety of different virtual reality technologies (desktop, projection or head mounted display (HMD) systems). In addition, the results from this method can be presented in a simple format to allow an easy feedback of user opinions and behaviours to virtual environment developers, providing contextual examples and an indication of the proportion of users experiencing usability problems. This facilitates a direct input of the evaluation data into the virtual environment development process.

Health and safety implications of virtual environments: Measurement issues

Investigations of the potential impact of virtual environments on user health and safety require a methodological framework to identify both the effects of VE participation and the role of influential factors in causing those effects. This first in a series of 12 experiments was designed to evaluate methods, but also provided preliminary data regarding psychological and physiological effects. This discussion centers upon the value of self-reports and performance measures and the general methodological problems of evaluating participation in virtual environments.

On the Right Track: Systematic Implementation of Ergonomics in Railway Network Control

Abstract: At a time of change for the railway networks of Europe we have been developing tools to assess ergonomics aspects of railway network control. This is within the Railway Ergonomics Control Assessment Package (RECAP). Among the developments have been an audit instrument (REQUEST), tools to assess situation awareness (RESA) and staff loading (RELOAD), and workshops to predict opportunities for human error and organisational failure across rail network operations. This research is discussed with respect to the context of UK railway operations and the need for an expanding tradition of cognitive ergonomics fieldwork. From the findings we draw some conclusions about the roles filled by signallers, electrical controllers and zone controllers within a perspective of distributed cognitive/social networks.

A theoretically motivated tool for automatically generating command aliases

A useful approach towards improving interface design is to incorporate known HCI theory in design tools. As a step toward this, we have created a tool incorporating several known psychological results (e.g., alias generation rules and the keystroke model). The tool, simple additions to a spreadsheet developed for psychology, helps create theoretically motivated aliases for command line interfaces, and could be further extended to other interface types. It was used to semi-automatically generate a set of aliases for the interface to a cognitive modelling system. These aliases reduce typing time by approximately 50%. Command frequency data, necessary for computing time savings and useful for arbitrating alias clashes, can be difficult to obtain. We found that expert users can quickly provide useful and reasonably consistent estimates, and that the time savings predictions were robust across their predictions and when compared with a uniform command frequency distribution.

Comparison of 2D and 3D representations for visualising telecommunication usage

This paper describes an empirical evaluation of one two-dimensional (2D), and two three-dimensional (3D) representations. These representations were developed to present customer behaviour information on telecommunications usage. The goal of the study was to investigate how the properties of these different but informationally equivalent representations supported information retrieval and problem solving using the database. Thirty-six participants performed a number of information retrieval and problem solving tasks, in one of three experimental conditions: 2D graph, 3D graph and 3D helix plot. Measures included performance time and accuracy and user attitudes concerning the usability of the displays. Despite certain navigational problems associated with the 2D representation, the results indicated a performance advantage for the 2D display compared with both 3D representations. Generally, the analyses revealed that the differences in representational characteristics have a significant effect on the level of cognitive effort required to perform the tasks.

Interaction with a desktop virtual environment: a 2D view into a 3D world

With the development of computer software and hardware in the past few years, it has been possible to produce effective training virtual environments on everyday personal computers with little expert training required for users or designers. However, the development of the equipment that enables this has brought little coinciding research on what features to include when designing these environments. Despite these increased advances in PC capabilities for desktop virtual environments (VEs), there are still limitations on the number of objects that can be programmed to be interactive, usually due to restrictions on programming time and cost. As a result, it is often left to the programmer to decide which of the objects included to increase the realism of the environment will be interactive and which aesthetic. The work presented in this paper is an experiment that aims to establish a guide for environment designers to aid effective environment interaction development by identifying key elements in a VE design.